Toe supporting device for a safety ski binding



June 24, 1969 I Q E ET AL I 3,451,687

'- TOE SUPPORTING DEVICE FOR A sAFmy SKI BINDING Filed Nov. 18, 1966 ISheet of 2 INV EN TORS lee/Amen; vim- 12 Hausa/9T HHSSLRHEIQ BY KJQQQQ C4? ATTORNEYS June 24, 1969 R. VOSTER ET I TOE SUPPORTING DEVICE FOR ASAFETY SKI BINDING Sheet Fil'e d Nov. 18 1966 FIGS INVENTORS Ram-mub'sree HERBIZET Immune/lea A ORNEW United States Patent V Int. Cl. A63c9/081 US. Cl. 280-11.35 11 Claims ABSTRACT OF THE DISCLOSURE Atoe-supporting device for use as a safety ski binding comprising a baseplate which is secured to the ski and a toe jaw for holding the toe of aski boot. The toe jaw is secured to the base plate by curved guide meansfor guiding the toe jaw so as to be pivotable in an arcuate directionabout the center of curvature of the guide means. The center ofcurvature of the guide is located in front of the guide as seen in thelongitudinal direction of the ski and is located outside and in front ofthe confines of the toe jaw. While pivoting to its releasing position,the toe jaw remains in engagement with and guides the boot and at firstcarries out only a movement in a substantially lateral direction for apredetermined distance prior to releasing the boot by movement in theforward direction. For this purpose, the arcuate guide is designed sothat its center of curvature is spaced from the toe portion of the skiboot a distance which is equal to about three-quarters to one andone-half the width of the ski. The device further includes a releasablelocking arrangement for normally maintaining the toe jaw in its centralposition on the ski. The two associated members of the locking deviceare preferably disposed slightly eccentrically to each other for thepurpose of compensating for any play which might exist between theassociated guide members of the arcuate guide.

The present invention relates to a toe supporting device for a safetyski binding which comprises a toeclamping jaw which, when it is actedupon by strong lateral forces, is adapted to pivot from its normalposition on the ski against a resilient force about an axis which islocated in front of the toe portion of the foot and extends verticallyto the upper surface of the ski.

If such a toe supporting device is of the conventional type in which thetoe-clamping jaw (hereafter simply called the toe jaw) is pivotallyconnected to a base plate on the upper sunface of the ski by means of apivot pin which is located underneath the toe jaw or within the confinesthereof, the disadvantage occurs that, when in a fall of the skier thetoe jaw is pivoted, for example, toward the right side from its normalposition, the part of the toe jaw which engages upon the left side ofthe toe portion of the ski boot will describe an are which, because ofthe relatively small turning radius of the toe jaw, is directedconsiderably toward the rear and will therefore also push the boot for aconsiderable distance toward the rear before it can disengage from theski binding. This movement of the boot not only delays but alsoendangers the release of the boot from the ski binding.

It is an object of the present invention to provide a toe jaw for asafety ski binding which is designed and mounted in a manner so as toimprove the safety of the ski binding and to insure especially in theevent of a fall of the skier that his boot will quickly andautomatically disengage from the binding.

Patented June 24, 1969 Another object of the invention is to providesuitable guiding means of the most simple and inexpensive constructionwhich in the event of a fall of the skier permit the toe jaw to pivotoutwardly very easily and along a relatively large turning radius fromits normal position on the ski, and which do not require any complicatedguiding curves or complicated fitting work. More particularly, it isalso an object of the invention to design these guiding means so as topermit the toe jaw when being released from its normal central positionon the ski to carry out a pivoting movement which at first extendssubstantially in a lateral direction and thereafter continues in theform of a more sharply curved move ment in the forward direction.

An important feature of the invention for attaining these objectsconsists in mounting the toe jaw on the ski, preferably on a support,for example, a base plate which is secured to the ski, soas to bemovable along an arcuate guide, the center of curvature of which islocated in front of the guide and more particularly at a point outsideof the confines of the: toe jaw.

The arcuate guide preferably forms a sector of a circle and its centerof curvature is located substantially within the central longitudinalaxis of the ski so as to permit the ski boot to disengage from the toejaw equally well toward the right and toward the left of the ski.

The invention attains the advantage that the toe jaw, while pivoting toits releasing position remains in engagement with and guides the bootand at first carries out only a movement for a certain distance in asubstantially lateral direction and thereafter carries out an increasingmovement in the forward direction. For attaining this movement it hasbeen found advisable to design the arcuate guide so that its center ofcurvature is spaced from the toe portion of the ski boot at a distancewhich is equal to approximately 4 to 1 /2 of the width of the ski, andpreferably to the width of the ski. The advantageous result is herebyattained that during the pivoting movement of the toe jaw the supportingpoint of the boot on the toe jaw which is most remote from the side ofthe jaw toward which the jaw is pivoted will at first be moved only fora short distance toward the rear, while the supporting point of the bootnearest the opposite side of the toe jaw will carry out a relativelyquick movement toward the front.

It is a further object of the invention to provide a very reliable andprotected construction and arrangement of the associated members of thearcuate guide. Further features of the invention for attaining thisobject consist in securing the inner guide member which may be made of asubstantially dovetailed cross section either to the ski or to the toejaw. If this inner guide member is secured to the toe jaw, theparticular advantage is attained that, when the toe jaw is pivotedtoward one side or the other, the guide surfaces are not exposed towardthe outside and are therefore better protected from being darnaged.Another embodiment of the invention which is of particular advantage isone in which the guide member of the arcuate guide which is secured tothe ski or to a base plate thereon only extends along the central partof the length of the associated guide member on the toe jaw when thelatter is in its normal position, and in which the toe jaw is providedwith lateral end walls which cover up and protect the first-mentionedguide member in lateral directions even when the toe jaw is pivotedfully outwardly. The associated members of the arcuate guide will thusbe protected from being bent or damaged in any other manner even duringthe most severe falls of the skier.

Further objects of the invention are to provide suitable means forlimiting the pivoting movement of the toe jaw and a releasable lockingdevice for normally maintaining the toe jaw in its central position onthe ski. The two associated members of this locking device arepreferably disposed slightly eccentrically to each other for the purposeof compensating for any play which might exist between the associatedguide members of the arcuate guide.

These and other features of the present invention will become moreclearly apparent from the following detailed description thereof whichis to be read with reference to the accompanying drawings, in which:

FIGURE 1 shows a top view of one embodiment of the toe-supporting deviceaccording to the invention;

FIGURE 2 shows a cross section which is taken along the line 22 ofFIGURE 1;

FIGURE 3 shows a cross section which i taken along the line 33 of FIGURE1;

FIGURE 4 shows another top view of the device as shown in FIGURE 1, butwith the toe jaw in the outwardly pivoted position;

FIGURE 5 shows a top view of another embodiment of the toe-supportingdevice according to the invention with the toe jaw in the outwardlypivoted position; while FIGURE 6 shows a cross section which is takenalong the line 6-6 of FIGURE 5.

As illustrated in FIGURES 1 to 4 of the drawings, the device accordingto the invention comprises a base plate 12 which is secured to the ski10 by means of screws 11 and is covered with a sheet or coating 13 of amaterial with a low coefficient of friction, for example, awaterrepellent plastic. On this sheet or coating 13, a guide member 14of a dovetailed shape is secured to the base plate 12 by means ofcountersunk rivets 15 or the like. This guide member 14 has an arcuateshape and the center M of its curvature is located outside of the baseplate 12 and substantially within the central vertical longitudirialplate of the ski. It is preferably made of light metal and has a centralbore into which a metallic sleeve 16 is inserted the bore 17 of whichserves as locking recess for receiving the locking member assubsequently described.

Guide member 14 guides the toe jaw 18 which is provided for this purposewith inwardly projecting parts 19 the walls of which surround the guidemember 14 adjacent to the base plate 12 like a dovetail guide and formguide surfaces 20 which are in engagement with corresponding guidesurfaces on guide member 14 so that the toe jaw 18 is movable along anare about the center of curvature M in the direction of the arrows X andX as shown in FIGURE 1. This arcuate movement of the toe jaw 18 islimited by a stop pin 21 which is mounted on base plate 12 and engagesinto an arcuate groove 22 which is provided in the lower side of jaw 18.This groove 22 has the same center of curvature M as the guide member 14and its opposite ends 22a and 2212 are adapted to abut against the stoppin 21.

The toe jaw 18 also carries a sole holder 23 which is adapted to engageupon the upper side of the toe portion of the sole of the ski boot 24and is adjustable by screws 25 to different heights from the uppersurface of the ski 10.

The toe jaw 18 is normally held in its central position as illustratedin FIGURE 1 by a releasable locking device 26 which essentially consistsof a locking member or ball 27 which is guided within a screwed-inbushing 29 and acted upon by a spring 28 which is inserted into andrests upon the bottom of a socket bore in a screw cap which is screwedinto the jaw 18 and locked thereto by a lock nut 31.

As shown in FIGURE 2, the axis of the guide bushing 29 and the center ofthe locking ball 27 of the locking device 26 are disposed slightlyeccentrically at a distance 2 to the axis of the locking recess which isformed by the bore 17. This has the advantage that the locking ball 27which is acted upon by the pressure of spring 28 tends to becomecentered in the bore 17 and thereby produces a transverse force on thetoe jaw 18 which acts in the longitudinal direction of the ski andcompensates any play on the guide surfaces 20 between the guide member14 on base plate 12 and the guiding parts 19 on the toe jaw 18.

The mode of operation of the device according to FIG- URES 1 to 4 is asfollows:

If a strong transverse force Q occurs on the boot 24, for example,because of a fall of the skier, this force causes the toe jaw 18 toswing against the resistance of the locking spring 28 in the outwarddirection, as indicated by the arrow X about the center of curvature M.The supporting point A of the boot sole on the toe jaw 18 is therebymoved in an arcuate direction, as indicated by the arrow a, and thepoint A is thereby moved forwardly very quickly, while the supportingpoint B of the boot sole moves in the arcuate direction b. Althoughduring this swinging movement the point B is also moved for a shortdistance I: toward the rear, this distance is so small in accordancewith the large turning radius r that it will not endanger or prevent theproper release of the boot.

Although by placing the center of curvature M still farther toward thefront and by thereby increasing the turning radius r, this distance itmay be even further reduced, this should not be done excessively sincethis would, in turn, decrease too much the forward displacement of thesupporting point A so that the movement of the toe jaw would then almostamount to a parallel displacement of the two points A and B in thelateral direction which would interfere with the proper release of theboot. By calculation and tests it has been found that the most desirablereleasing conditions will be attained if the radius r correspondsapproximately to the width of the ski and may vary between a distance of0.75 to 1.5 of this width.

FIGURE 4 illustrates the toe jaw 18 when pivoted as far as possibletoward one side as determined by the engagement of the stop pin 21 Withthe end surface 22b of groove 22.

FIGURES 5 and 6 illustrate a modification of the invention in which thetoe jaw 18 is guided inversely to the manner as shown in FIGURES l to 4insofar as the toe jaw 18 is provided with the inner guide member 32 ofthe arcuate guide and the base plate 12 is provided by means of rivets33 with the outer guide member 34 which embraces the dovetailedprojections 35 on the guide member 32 by means of its correspondingprojections 36. The outer guide member 34 extends, however, only along apart f of the entire guide length, namely, only along that part which,when the toe jaw is fully pivoted toward the right, as shown in FIGURE5, or toward the left, is still located underneath the toe jaw so thatthe guide surfaces 20 are fully protected from being damaged when thetoe jaw is fully pivoted toward one side or the other. The toe jaw 18 isfurther provided with end walls 37 which close the ends of the recessesat both sides of the guide member 32 and also protect the arcuate guideat least at both sides of the toe jaw or in all directions when the toejaw is in its central position. The parts of the arcuate guide are thenfully encased in the upward, downward and lateral directions and thusprotected from the entry of snow, ice, dirt or other foreign matter.

If the base plate 12 also of the device according to FIGURES 5 and 6 iscovered with a sheet or coating 13 which consists of a water-repellentmaterial with antifriction properties, it is possible to reduce oreliminate entirely the danger that the contact surfaces of the movabletoe jaw 18 and the base plate 12 might become covered with ice andfreeze together.

Having thus fully disclosed our invention, what we claim is:

1. A toe-supporting device for a safety ski binding comprising a toe jawfor normally engaging upon the toe portion of a ski boot in thelongitudinal direction of the ski, and coacting first and second curvedguide means for guiding the toe jaw during pivotable movement thereof inan arcuate direction about the center of curvature of said guide means,the center of curvature of said first and second curved guide meansbeing disposed in front of said guide means as seen in the longitudinaldirection of the ski and located outside and in front of the confines ofsaid toe jaw, said first curved guide means being secured to the ski andthe second curved guide means being secured to the toe jaw.

2. A toe-supporting device as defined in claim 1 wherein said firstcurved guide means comprises a first fitting secured to the ski andhaving formed thereon first guiding means of substantially dovetailcross-section shaped as a freely terminated segment of a circular freearc and said second guiding means is formed on said toe jaw ofcorresponding complementary dovetail cross section relative to saidfirst guiding means and shaped as a freely terminated segment of acircular free are, said first and second guiding means being intermeshedone within the other for slidably securing said toe jaw to said firstfitting.

3. A toe-supporting device as defined in claim 2, in which said firstguiding means comprises a ridge having a substantially dovetail-shapedcross section on said fitting disposed between a correspondingcomplementary dovetail-shaped grooved that comprises said second guidingmeans on said toe jaw.

4. A toe-supporting device as defined in claim 2, in Which said secondguiding means on said toe jaw comprises a ridge having a substantiallydovetail-shaped cross section disposed between a correspondingcomplementary dovetail-shaped groove that comprises said first guidingmeans on said fitting, as seen in the longitudinal direction of the ski.

5. A toe-supporting device as defined in claim 2, in which said firstguiding means on said fitting only extend along a central part of thearcuate length of said second guiding means on said toe jaw, and furthercomprising side walls on the ends of said second guiding means limitingthe arcuate length thereof so that said toe jaw is pivotable in oppositearcuate directions from its central position until one of said sidewalls engages upon one of the ends of said first guiding means.

6. A toe-supporting device as defined in claim 2, further includinglocking means for normally maintaining said toe jaw in a centralposition on said ski, said locking means comprising a locking membermoveably supported on said toe jaw, a bore formed on said first fitting,and resilient means for pressing said locking member at least partlyinto said bore with said toe jaw normally located in its centralposition.

7. A toe-supporting device as defined in claim 1, in which said firstand second guide means have a circular curvature and said center ofcurvature is located at least closely adjacent to the central verticallongitudinal plane of the ski.

8. A toe-supporting device as defined in claim 1, further comprisingmeans for limiting the extent of the pivotability of said toe jaw ineither direction from its central position on said ski, said means forlimiting the extent of the pivotability of said toe jaw relative to saidski comprising an elongated arcuate recess formed on one of said parts,and a projection from the other of said parts extending into said recessand adapted to engage upon one of the ends of said recess upon said toejaw being pivoted in one direction to the extent of pivotabilitydesired.

9. A toe-supporting device as defined in claim 8, in which saidelongated arcuate recess extends parallel to said curved guide means andopens in the downward direction, and said projection extends upwardlyfrom said ski into said recess.

10. A toe-supporting device as defined in claim 1, in which said centerof curvature is located at a distance of /1 to 1 /2 of the width of theski in front of the points on said toe jaw adapted to engage with thetoe portion of a ski boot.

11. A toe-supporting device for a safety ski binding comprising a toejaw for normally engaging upon the toe portion of a ski boot in thelongitudinal direction of the ski, and curved guide means for guidingthe toe jaw so as to be pivotable in an arcuate direction about thecenter of curvature of said guide means, the center of curvature of saidguide means being disposed in front of said guide means as seen in thelongitudinal direction of the ski, said curved guide means comprising afirst fitting secured to the ski and having formed thereon first guidingmeans, second guiding means formed on said toe jaw for guiding said toejaw so as to be slidable along said first guiding means, at least one ofsaid first and second guiding means being bent concavely toward thefront, locking means for normally maintaining said toe jaw in a centralposition on said ski, said locking means comprising a locking membermoveably supported on said toe jaw, a first bore formed on said firstfitting, and resilient means for pressing said locking member at leastpartly into said first bore with said toe jaw located in its centralposition, said locking means further comprising guide means for saidlocking member, said locking member guide means having a guide borecontaining said locking member and extending substantially verticallywith respect to the upper surface of said ski, the axes of said guidebore and said first bore being parallel but offset with respect to eachother by a fraction of the diameter of said first bore.

References Cited UNITED STATES PATENTS 3,079,164 2/1963 De Place280-1135 3,188,104 6/1965 Magnin 28011.35

3,288,476 11/1966 Ramillon 280-1135 FOREIGN PATENTS 1,192,576 5/1959France.

1,365,561 5/1964 France.

OTHER REFERENCES German printed application DAS 1,000,723, January 1957,Wunder, 280-1135 (HA).

KENNETH H. BETTS, Primary Examiner.

JOHN A. PEKAR, Assistant Examiner.

